# 一只狗   小黑   age 3
class Dog:
    name=''
    age=0

    def speck(self,xinqing='平静'):
        print(f'我是{self.name},今年{self.age}岁.我很{xinqing}')

xiaohei=Dog()
xiaohei.name='小黑'
xiaohei.age=3


xiaohei.speck( '开心' )